The worst time to pass south through the Hooksett toll booth historically is between noon and 4 p.m. Monday.

A last-minute booking at one of 20 state campgrounds was possible but not guaranteed.

And if you want to avoid the worst crowds at Brown's Lobster Pound in Seabrook, order the seafood plate between 7 and 9 p.m.

People waking up in the middle of the Memorial Day weekend will plan their holiday factoring in the weather, which so far favors donning a sweatsuit rather than a swimsuit.

The battle over which temperature would be higher - on land or in the ocean at Hampton Beach - ended in a draw Saturday with both in the high-40s. But the air temperature should win out today with the high approaching 60 degrees - or about 15 degrees Celsius for our Canadian friends.

No matter which prevails, Hampton Beach will shoot off fireworks at 9:30 tonight.

Before the rain stops, people can shop at more than 200 outlet stores around the state - from Adidas (footwear) to Zwilling J.A. Henckels (kitchen gadgets) - centered in Merrimack, Tilton and North Conway.

"With the forecast as it sits right now, we couldn't be any happier," said Eric Proulx, general manager of Tanger Outlets in Tilton.

Rainy weather and out-of-state tourists translate into busier cashiers, he said. And there's a roof to protect shoppers picking through offerings at this weekend's sidewalk sale in Tilton.

"If their agenda had something to do with outdoor recreation or the lake, those are going to be put on the back burner and shopping will be moved to the forefront," Proulx said.

More than 500,000 tourists are expected over the weekend, mostly from New York and New England.

Memorial Day is one of the four busiest weekends on the state's turnpike system, along with the Fourth of July, Labor Day and Columbus Day weekends, according to Bill Boynton, spokesman for the state Department of Transportation.

This year, motorists on Interstate 93 can take advantage of open-road tolling in Hooksett if they have E-ZPass. That means they can maintain their speed at 65 mph going through the toll station.

For last year's Memorial Day Weekend, 1,219,517 vehicles passed through a toll somewhere in New Hampshire between Friday and Monday - including 279,465 vehicles on the holiday Monday. During that Monday's peak, more than 4,000 vehicles heading south on Interstate 93 went through the Hooksett toll booth each hour between noon and 4 p.m.

The high temperature in Concord should average 72 degrees with an average low of 46, but can vary widely this time of year.

For May 26, the mercury hit a record 96 degrees in 2010 in Concord. For May 27, the record high reached 93 degrees in both 1914 and 1944. But it can get colder than this weekend, as well. For May 26, the record low dipped to 28 degrees in 1956 while May 27, 1969, saw a record low of 24.

Weather helps determine what state park will be most populated. Summer-like weather would make Hampton Beach State Park the most popular, according to Amy Bassett, spokeswoman for the state Division of Parks and Recreation. "I guess the most popular based on the weather forecast, obviously it's not going to be Hampton Beach," she said. "Franconia Notch is always a safe bet no matter what the temperature. The Flume's going to be spectacular based on all the rain. The falls are going to be incredible."

Most state parks cost $4 to $5 for people 12 and older and $2 for those age 6 to 11, with littler ones free. The Flume costs $15 for adults and $6 for ages 6 to 11.

"I know we've had some cancellations and we saw some people booking when they saw cancellations," Bassett said of state campground sites. Rates range from $23 to $50 a night, with $25 the average.

The weather also dictates which alcoholic spirits sell the best.

Hot and sunny weather means "we will do well for tequila for your margaritas," said Mark Roy, spirits marketing specialist at the State Liquor Commission. "I'm thinking this weekend we'll probably see a pretty big spike in vodka and rum."

He predicted "a spiced-rum weekend" with the cooler weather. Liquor stores are open today and Monday, with closing times varying by locations.

The commission also regulates about 3,000 places to purchase beer in New Hampshire, including 1,200 locations to buy a six-pack to go.

For those diverted by the rain, Funspot in Laconia offers 615 arcade games, from traditional pinball machines to the Harpoon Lagoon, the newest video game that pays out tickets good for redeeming prizes.

"During this time of year, when it gets rainy and stuff, we get pretty swamped in here, especially on Memorial Day," said floor manager Tyler Blake.

B.J. "Doc" Noel, president of the Hampton Area Chamber of Commerce, said private parking lots get $5 to $10 at Hampton Beach, sometimes more during warm weather days. Parking at the meters remains the same at $2 per hour.

"I need some sunshine over here; we all do," Noel said.

Hotel bookings were solid and whether people cancel will depend partly on the individual policy of the establishment, he said. Bad weather will drive people to go shopping.

At Brown's, the most popular item is the $18.95 seafood plate. For $3 more, you can add lobster.

"We usually do pretty well on Memorial Day regardless of the weather," said Kaleb Brown, the owner's grandson. "Whenever it's sunny and warm, we do better down here."